With multi-gear stage transmissions, gear shifting devices are used in order to couple transmission components of the respective transmission with each other in a torque-proof manner for the presentation of each corresponding transmission ratio relationship. Thereby, usually one shift element is assigned to a gear shifting device, which, depending on the specific arrangement, makes a friction or positive-locking coupling (e.g., a dog clutch) of the respective assigned transmission components upon actuation. Thereby, the respective shift element is typically provided, in a torque-proof and axially displaceable manner, on one of the two transmission components to be connected in a torque-proof manner, and is displaced into a respective shift position by means of an actuator system, in which the desired, torque-proof coupling is realized under the prior reduction of any possible prevailing difference in rotational speed between the two transmission components. Depending on the specific arrangement of such actuator system, such an axial shift movement of the respective shift element is thereby initiated mechanically, hydraulically, pneumatically, electrically or through mixed forms.
A gear shifting device of an automated gearbox arises from DE 196 27 980 A1, through which a first rotatably drivable transmission component can be coupled, in the form of a transmission shaft, with several transmission components that are adjacently located. In the cited case, such additional transmission components comprise gear wheels that are rotatably mounted on it. In addition, several shift elements in the form of clutch sleeves are arranged on the transmission shaft in a torque-proof and axially displaceable manner, whereas each of the clutch sleeves is composed of a ring-shaped body, which is provided on an inner circumference with an axially running toothing and is guided through such toothing to a corresponding toothing on the sides of the radial inner transmission shaft.
Each of the sliding sleeves may now, in each case, move axially between a neutral position, in which the respective sliding sleeve does not couple any of the two gear wheels, located axially on both sides, with the transmission shaft, and two shift positions in which, in each case, the transmission shaft is coupled in a torque-proof manner with one gear wheel under the prior reduction of a difference in rotational speed. Thereby, in the present case, the axial shift movements of the individual sliding sleeves are presented through an electric motor, intermediate transmission ratio stages, and a shift drum in interaction with a shift fork assigned to the individual clutch sleeves. Thereby, through the electric motor, by means of the intermediate transmission ratio stages, this brings about, on the one hand, an opening of the separating clutch upstream of the transmission shaft and, on the other hand, a corresponding turning of the shift drum at the same time.
The shift drum is provided on a radial outer side with groove-like shift gates, which are designed to have a changeable axial course, at least in sections, and in which one shift pin of the respective shift fork runs. If the shift drum is set in rotational motion through the electric motor by means of intermediate transmission ratio stages, the course changeable in an axial direction of the respective shift gate, through the shift pin running thereon, brings about an axial sliding movement of the respective shift fork, which is translated into a corresponding axial displacement of each associated clutch sleeve on the transmission shaft. As a result, the respective clutch sleeve is moved axially between its respective neutral position and one of the possible shift positions. Thereby, the shift gates on the shift drum are designed to be changeable in an axial direction in such a manner that, upon a constant rotational motion initiated by the electric motor, a sequential shifting of the individual gears of the automated gearbox takes place with the respective open separating clutch.